package org.example;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class sum3_15 {
    public List<List<Integer>> threeSum(int[] nums) {
        Arrays.sort(nums);
        List<List<Integer>> result = new ArrayList<List<Integer>>();
        if(nums[nums.length-1]<0)
            return result;
        for(int i=0; i<nums.length-2; i++) {
            if(nums[i]>0){
                break;
            }
            if(i>0 && nums[i]==nums[i-1])
                continue;
            int left = i+1;
            int right = nums.length-1;
            while(left<right){
                int sum = nums[i]+nums[left]+nums[right];
                if(sum == 0){
                    result.add(Arrays.asList(nums[i],nums[left],nums[right]));
                    while(left<right && nums[left]==nums[left+1])
                        left++;
                    while(left<right && nums[right]==nums[right-1])
                        right--;
                    left++;
                    right--;
                }
                else if(sum<0){
                    left++;
                }else {
                    right--;
                }
            }
        }
        return result;

    }
}
